Continuous process for producing bituminous emulsions



CONTINUOUS PROCESS FOR PRODUCING Y BITUMINOUS EMULSIONS Eldon C. Brown, Rutherford, Wilfred H. Driesen, Mountain Lakes, and Jacob S. Gnepet,,Clifton, N. J., assignors to The Patent and Licensing Corporation, New York, N. Y.', a corporation of Massachusetts No Drawing. Application August 21, 195:,

Serial No. 305,714

13 Claims. (Cl. 252-311.5)

This invention relates 'to a process for the production of emulsions, and more particularly has reference to the production of emulsions of a bitumen such as asphalt in an aqueous vehicle, utilizing clay as a dispersing agent and to the product produced thereby.

Emulsions of' bituminous materials such as pitch and asphalt in an aqueous vehicle are well-known. Those in commercial production generally fall into two classes; one utilizing a soap or detergent as the dispersing agent, and the other utilizing a mineral colloid or clay as the dispersing agent. In many applications, the clay type emulshirts are particularly advantageous. Production of these emulsions, however, involves rather critical limitations on conditions in the process of making theemulsion. They have previously been made by a method utilizing a particular vortex mixer and auxiliary cooling and mixing equipment. They have also been of a large asphalt particle size. t

While soap-bitumen emulsions were made successfully, various attempts to produce these bitumen-clay emulsions on attrition type colloid mill equipment were without success. These bitumen-clay emulsions should have the ligno sulphonate, one

2,782,169 Patented Feb. 19, 1957 mixing water and clay together with sufiicient acidic material to produce a pH of 4.0 to 4.5 and passing this mixture together with molten bitumen continuously through an attrition-type colloid mill. Preferably, there should alsobe added a viscosity adjusting agent such as of which'is known commercially as Marasperse. i

The following example illustrates a preferred embodiment of the invention, but it will be understood that substitutions and variations may be made within the scope of the claims.

' Example In a mixing vessel equipped with an agitating device there was placed 3.3 parts by weight of bentonite, 0.0875 part potassium bichromate, 0.08 part orthophosphoric acid, 0.025 part ligno sulphonate (Marasperse N)- and 46.0 parts water. The mixture was heated to 75 85 F. and the pH further adjusted to the range 4.04.5 by add ing additional ortho-phosphoric acid. In a separate heated tank 50.5 parts 100-120 penetration and 105-1 15 M. P. asphalt is heated to atemperature of 190-200? F.

The contents of each tank are fed into a Charlotte colloid mill. The product from the colloid mill is a dispersion of a buttery consistency, suitable for packaging and having an asphalt particle size primarily in the range 3 to 10 microns.

properties of forming a dry film of the composition having a honey-comb structure of the character which renders the dry film resistant to flow in temperature in excess of the softening point of the bitumen. In addition, adried film should be resistant to re-di'spersion in water? The emulsion itself should contain as little water as possible, while maintaining a sufficiently low viscosity for easy application both fromthe point of view of'the ease of drying the film andfrom the pointof'view'ofkeepingth'e c'ostiof shipping-down, also easel-of handling, barreling, etc. i f It is desirable to produce a product of smaller particle size than heretofore, including among the advantages the maintenancemf'a constant viscosity during storage. The

Instead of the acidic materials employed in the example for controlling the pH, there may be utilized acids such as oxalic, chromic, hydrochloric, benzoic, etc. Acid salts such as aluminum sulphate, sodium phosphate, calcium acid phosphate, etc. may be used either alone or in admixture with an acid.

The use of a viscosity adjusting agent is important in order to obtain a dispersion which is sufficiently mobile, for use without the necessity of the additional step of agitating the dispersion at reduced temperature in a pug mill or the like to decrease the viscosity. Besides the lignosulphonate disclosed in the example, other; suitablevis- Icosity adjusting agents may be used which are highly soluble but not highly ionizable organic compounds containing hydroxyl or carboxyl groups, such as pyrogallic acid.

The water content of the composition is in the range. of 44% to by weight. Lower water content gives an extremely viscous or even inverted emulsion whereas vhigher watercontents yield emulsions which aremore emulsion should bemore stable than the soap type emul- 1 sion in the presence of such materials as cement. I 'It is,itherefore, an objct 'of the'present invention to provide a process for continuously producing a bitumenclay emulsion iii water o'n attritiontype colloid mill isq pme l It isa fiirther-object' of thejpresnt invention to provide :aprocess for producing a-bit'umen-clay emulsion of'a smallparticle size.

It is a further object of th' presentinvention to provide a process for pr iduc'in'g numbed-clay emulsion in water 1 wherein the dispersion contains not more than 50% water. 3 it is a further objectof the.p resent;. inyention to provide bitumen-clay emulsion ing water wherein the emulsion mains not more than 50% water, wherein the dispersion from the emulsion is resistant to flow and re-dispersion.

These and other objects are attained by the present invention which relates to a new clay type bituminous emulsion and to a continuous process for producing bituminous emulsions containing clay, which comprises difficult to dry and more expensive to transport and are not asfinely dispersed. I v I g a The b'tumen as used here may comprise, forexample,

asphalt or other bituminous material,- either of a solid or semi-solidconsistency, and may be either native asphalt or asphalt of the so-called artificial variety produced by refining residuums. In place of asphalts, it is possible to disperse materials of an analogous nature such as coal tar .pitch.

Preferred asphalts may have penetrations of from!) to V as high as 200 at 77 F; .(ASTM -25) and. softening or melting point from about 70F. ,to 200 A range of emulsions canbe made from material that is'liquid at 'erniilsification will, of course, vary with the melting point of the asphalt. For example, emulsification temperatures of F. are suitable for 100 to 130 F. melting point asphalt whereas emulsification temperature of 190 to 200 F. are desirable for 180 to F. asphalt.

While the example has mentioned the Charlotte colloid mill, theterm colloid mill as used herein includes dis persers and homogenizers such as the attrition type Lancaster disperser and other devices which tend to shear particles or pass them between small clearances asitr the device. as.- mentioned. These devices are preferably fed. under pressure, but not necessarily so. The devices are well-known. to. the art, and are not per se part ofthe present invention.

Where the term emulsion has been used. herein, itisintended to include aqueous suspensions of solid or semi.- solid materials which, are dispersed in a line state of. subdivision;

It isa particularly important characteristic of thepresent invention that in its preferred form, the emulsion leaves the colloid mill with a substantially low viscosity, and it may be moved into containers without the additional step of, milling'it to-reduce the viscosity.

It will" beunderstood that the emulsions produced by Y the present process are soap free, relying entirely on the ticularly suitable as an asphalt tile cement and adhesive and waterproof coating in roofing and flooring. It may be admixed with cement to produce a mastic for coating floors; It maybe used to spray the inside of tanks to make them waterproof. It may be used to spray or otherwise'coat wall surfacing to waterproof them, and as a base for embedding granule weathering material on the wall. The emulsion may be filled With asbestos or the like and used as an insulating coating for railroad cars, boats and the like. Itmay be combined with sand. or other fillers and used as sound deadening material and undercoating for automobiles.

As used herein, the particle size range 3 to microns means that more than half of the material will fall in this range and "that the average of all particles will be in this range. j

The pH of the clap slip is an important factor in the process. The final pH of the entire emulsion is not critical since certain asphalts may raise the final pH as high as 8-; If the pH of the clay slipis below 4.0, the viscosity of the emulsion increases undesirably. Higher pH than 415 tends to prevent formation of a stable emulsion.

Among the many advantages'of the product are in- 4. An asphaltic emulsion containing Bentonite as the emulsifying agent and having the majority of asphalt particles of a size from 3 to 10 microns, and having a water content of 44% to 5 0% by weight.

5. An asphaltic emulsion containing clay as the emulsifying agent and having the majority of asphalt particles of a size. fromi to l0%mic1:0ns,.an having a water content of 44% to %-byweight, and containing lignon sulphonate asa thinner.

6. An asphaltic-ehmlfsion containing clay as. the emulsifying agent and havingthenrajorityof asphalt particles of a size from;3 .to--1-OmicrOns-,;andhaving a water content of 44% to 50% by weight, said asphalt having a melt point in therange-LOS A'TS', anda penetration of -120.

7. An asphaltic emulsion containing Bentonite as the emulsifying agent and having the majority of asphalt particlesof a. size. from 3, to 10,. mierons,.and having a water content; of 44% to'50% by weight, and containing lignonsulphonate asa. thinner, said. asphalt having amelt point in the. range -11S- F. and a penetration of 100-120.

8. A process for the production of an asphalt-clay emulsion comprising I, simultaneously passing through an attrition type colloidmill a molten asphalt and a clay slip comprising Bentonite clay and water adjusted to a pH in therange 4.0 to 4.5 the watercomprising 44% to 50% by weight of the finished emulsion. V V

V 9-. A. process for the. production of a bitumen-clay emulsion comprising simultaneously passing through an attrition type. colloid mill a molten bitumen and a clay slip comprising clay and water adjusted to a pH in. the range 4.0 to 4.5, the water comprising 44% to 50% by weight ofthe'finished emulsion.

10; A process for the production of an asphalt-clay emulsion. comprising simultaneously passing through an attrition. type. colloid mill. a molten asphalt and a clay slip comprising clay and water adjusted to a pH in the range 4.0 to 4.5 saidasphalt having a melt point in the phonate' anda clay slip comprising clay and wateredjusted to a pH in the range4.0 to 4.5 the water comprising 44% to 50% byweight ofthe finishedemulsion.

cluded'animproved'bond; an improved penetration, and

resistance to breakdown with electrolites such as are presentin-cernent. Dried' films have a desirable honey-comb of a size from 3 to 10 microns;

2. A bituminous emulsion containing clay as the emulsifying agent and having'the majority of bitumen particles bf a size-from 3 to 10 microns, and havinga watercontent of 44% to 50% byweight.

3 An asphaltic-einulsion containingclay as the emulsifying agent and having the majority of asphalt particles of a-sizefrom 3m .10 microns, and having a watercontent at 44% to-50% by weight.

phonate and a clay slip comprising clay and water. ad-

justed to a pH in the range 4.0 to 4.5, the watercomprising 44% to 50% by weight of the finished emulsion, said asphalt'having a melt point in the range 105 F. and

a penetration of 100-120.

eminded the til or thispatent STATES PATENTS 1,918,,7-59

. Kirsehbraun July 18, 1933 2,481,374 Wat-ts ct al.- Sept. 4,- 1949 2,521,542 Schwartz Sept. '5, 1950 2,620g 3'12 Manzer Dec; 2, I952 

1. A BITUMINOUS EMULSION CONTAINING CLAY AS THE EMULSIFYING AGENT AND HAVING THE MAJORITY OF BITUMEN PARTICLES OF A SIZE FROM 3 TO 10 MICRONS.
 8. A PROCESS FOR THE PRODUCTION OF AN ASPHALT-CLAY EMULSION COMPRISING SIMULTANEOUSLY PASSING THROUGH AN ATTRITION TYPE COLLOID MILL A MOLTEN ASPHALT AND A CLAY SLIP COMPRISING BENTONITE CLAY AND WATER ADJUSTED TO A PH IN THE RANGE 4.0 TO 4.5 THE WATER COMPRISING 44% TO 50% BY WEIGHT OF THE FINISHED EMULSION. 